U.S. patent number 5,584,815 [Application Number 08/424,660] was granted by the patent office on 1996-12-17 for multi-cartridge medication injection device.
This patent grant is currently assigned to Eli Lilly and Company. Invention is credited to David L. Karshmer, Christopher O. Lada, Matthew Marsh, Gerhard E. F. Pawelka, Stephen J. Schoenberg, Christopher J. Stringer.
United States Patent |
5,584,815 |
Pawelka , et al. |
December 17, 1996 |
Multi-cartridge medication injection device
Abstract
A multi-cartridge dispenser for delivering two liquid
medications through a single needle. The dispenser includes
independent dual channel metering mechanism, dual channel drive
mechanisms, and dual channel lock and pullback mechanisms. The wing
must be in its "up" position for metering to take place. The wing
reciprocatingly moves a driver between a pre-injection position and
a post-injection position to reciprocatingly advance the leadscrews
upon an injection stroke. The dosage indicator automatically
rotates to its initial zero position upon the injection stroke. The
lock and pullback mechanism automatically prevents rotation of the
leadscrew upon metering and injection. It also locks out the
cartridge retainers so that the retainers can be removed from the
housing only while the wing is in its "down" position. The pullback
sleeve unloads a pullback key during a cartridge change in order to
enable the leadscrew to be spun freely back to its home
position.
Inventors: |
Pawelka; Gerhard E. F.
(Lexington, MA), Stringer; Christopher J. (San Francisco,
CA), Marsh; Matthew (San Francisco, CA), Karshmer; David
L. (San Francisco, CA), Lada; Christopher O. (Palo Alto,
CA), Schoenberg; Stephen J. (Redwood City, CA) |
Assignee: |
Eli Lilly and Company
(Indianapolis, IN)
|
Family
ID: |
23683409 |
Appl.
No.: |
08/424,660 |
Filed: |
April 19, 1995 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
333207 |
Nov 2, 1994 |
5478323 |
|
|
|
335674 |
Nov 8, 1994 |
|
|
|
|
41758 |
Apr 2, 1993 |
|
|
|
|
Current U.S.
Class: |
604/191; 604/135;
604/186; 604/211; 604/506; 604/518; 604/83 |
Current CPC
Class: |
A61M
5/19 (20130101); A61M 5/24 (20130101); A61M
5/2448 (20130101); A61M 5/31553 (20130101); A61M
5/31581 (20130101); A61M 5/2466 (20130101); A61M
5/31535 (20130101); A61M 5/31541 (20130101); A61M
5/31543 (20130101); A61M 5/31561 (20130101); A61M
5/31563 (20130101); A61M 5/3157 (20130101); A61M
2005/2407 (20130101); A61M 2005/2488 (20130101); A61M
2205/581 (20130101); A61M 2205/582 (20130101); A61M
2205/583 (20130101); A61M 2205/585 (20130101) |
Current International
Class: |
A61M
5/24 (20060101); A61M 5/19 (20060101); A61M
5/315 (20060101); A61M 005/00 () |
Field of
Search: |
;604/191,90,82-83,211,232,237,205,186,240,207-209,135-137 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
2108691 |
|
Aug 1993 |
|
CA |
|
2074565 |
|
Jan 1995 |
|
CA |
|
0058536 |
|
Feb 1982 |
|
EP |
|
0498737A1 |
|
Feb 1992 |
|
EP |
|
0627229A1 |
|
May 1994 |
|
EP |
|
1070784 |
|
May 1957 |
|
DE |
|
3903315A1 |
|
Aug 1989 |
|
DE |
|
1198214 |
|
Jul 1970 |
|
GB |
|
2172937 |
|
Oct 1986 |
|
GB |
|
WO92/10425 |
|
Jun 1992 |
|
WO |
|
WO92/18179 |
|
Oct 1992 |
|
WO |
|
WO93/10838 |
|
Jun 1993 |
|
WO |
|
WO94/11039 |
|
May 1994 |
|
WO |
|
WO94/15120 |
|
Jul 1994 |
|
WO |
|
Primary Examiner: Green; Randall L.
Assistant Examiner: Van Over; Perry E.
Attorney, Agent or Firm: Baker & Daniels
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of U.S. application Ser. No.
08/333,207, filed Nov. 2, 1994, now U.S. Pat. No. 5,478,323,
entitled MANIFOLD FOR INJECTION APPARATUS, and a
continuation-in-part of U.S. patent application Ser. No.
08/335,674, now abandoned, filed Nov. 8, 1994, entitled MANIFOLD
MEDICATION INJECTION APPARATUS AND METHOD, which is a continuation
of application Ser. No. 08/041,758, Apr. 2, 1993, now abandoned.
Claims
What is claimed is:
1. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a container mounted to said housing and including a piston, an exit
and an injectable product between said piston and said exit;
a drive stem disposed in said housing and engageable with said
piston;
a tubular element threadably coupled to said drive stem such that
said tubular element is rotatable with respect to said drive stem,
wherein relative rotation between said tubular element and said
drive stem controls the amount of telescopic extension of said
drive stem from said tubular element to establish a set dosage of
injectable product to be delivered, wherein a first coupling
element is secured to said tubular element for rotation with said
tubular element;
a drive assembly secured to said tubular element and movable with
respect to said housing between a pre-injection position and a
post-injection position for axially moving said drive stem with
respect to said housing, to drive said piston within said container
upon movement of said drive assembly from said pre-injection
position to said post-injection position; and
a user-engageable dose setting assembly including a second coupling
element engageable with said first coupling element for rotation
with said first coupling element to enable a user to effect said
relative rotation between said tubular element and said drive stem,
wherein said first coupling element is in engagement with and
rotatable with said second coupling element while said drive
assembly is in said pre-injection position, and said first coupling
element is axially spaced from said second coupling element while
said drive assembly is in said post-injection position, thereby
preventing a user from setting a dose while said drive assembly is
in its post-injection position.
2. The apparatus of claim 1, wherein said piston is axially movable
in said container toward said exit to define an axis of ejection of
said injectable product, wherein said drive assembly includes an
actuator movable in a direction transverse to said axis of ejection
for moving said drive assembly between said pre-injection position
and said post-injection position.
3. The apparatus of claim 1, wherein said dose setting assembly is
rotatable between an initial radial position and a final radial
position for establishing said set dosage of injectable product to
be delivered while said drive assembly is in said pre-injection
position, wherein a spring is secured to both said housing and said
dose setting assembly for automatically biasing said dose setting
assembly to said initial radial position upon movement of said
drive assembly from said pre-injection position to said
post-injection position.
4. The apparatus of claim 3, wherein said dose setting assembly
comprises a sleeve-like indicator dial, wherein a first axial end
of said dial is secured to a user-engageable knob and a second
axial end of said dial comprises a set of ratchet teeth for
engagement with said first ratchet element of said drive
assembly.
5. The apparatus of claim 4, wherein said dose setting assembly
includes a bearing element between said knob and a portion of said
dial, said bearing element being secured to said housing and said
knob and dial being rotatable with respect to said bearing element,
wherein a first end of said spring is secured to said bearing
element and a second end of said spring is secured to one of said
knob and said dial.
6. The apparatus of claim 4, wherein said dial includes a plurality
of numerals spaced thereabout, wherein said housing includes an
opening therein and said dial is arranged in said housing such that
a numeral appears in said opening, thereby indicating to the user
the number of dosage units constituting said set dosage.
7. The apparatus of claim 6, wherein the numeral 0 appears in said
opening while said dose setting assembly is in said initial radial
position.
8. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a container mounted to said housing and including a piston, an exit
and an injectable product between said piston and said exit;
a tubular element disposed in said housing, said tubular element
including an internally threaded surface;
a drive stem telescopingly extending through said inner diameter
surface and including a first axial end engageable with said
piston, a second and opposite axial end comprising an enlarged
diameter portion, and an externally threaded surface between said
first end and said second end, said externally threaded surface in
engagement with said internally threaded surface of said tubular
element;
a nut secured to said drive stem for restraining rotation of said
drive stem upon rotation of said tubular element, said drive stem
being axially movable with respect to said tubular element upon
rotation of said tubular element, wherein relative rotation between
said tubular element and said drive stem controls the amount of
telescopic extension of said drive stem from said tubular element
to establish a set dosage of injectable product to be delivered,
wherein said amount of telescopic extension of said drive stem from
said tubular element is at a maximum upon said enlarged diameter
portion of said drive stem engaging said internally threaded
surface of said tubular element; and
a drive assembly coupled to said drive stem for axially moving said
drive stem to drive said piston.
9. The apparatus of claim 8, wherein said drive assembly is secured
to said tubular element, said tubular element being axially
stationary upon rotation of said tubular element.
10. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a container mounted to an end of said housing and including a
piston, an exit and an injectable product between said piston and
said exit;
a drive stem disposed in said housing and drivingly coupled to said
piston;
a drive assembly coupled to said drive stem for moving said drive
stem to drive said piston within said container;
a rotatable piece secured to said drive stem for rotation with said
drive stem;
a locking sleeve disposed about said drive stem and coupled to said
rotatable piece to restrict rotation of said rotatable piece, said
rotatable piece and said locking sleeve being in engagement with
one another while said container is mounted to said housing to
prevent rotation of said rotatable piece and said drive stem;
and
a disengaging mechanism coupled to at least one of said rotatable
piece and said locking sleeve for automatically disengaging said
locking sleeve from said rotatable piece upon removal of said
container from said housing, thereby permitting said rotatable
piece and said drive stem to be rotated with respect to said
housing.
11. The apparatus of claim 10, wherein said disengaging mechanism
comprises a locking device keyed to said locking sleeve and movable
between a locked position and an unlocked position, wherein in said
locked position, said locking device is in tight engagement with
said rotatable piece thereby forcing said rotatable piece into
locking engagement with said locking sleeve for preventing rotation
of said rotatable piece and drive stem, and wherein in said
unlocked position, said locking device is spaced from said
rotatable piece, thereby permitting said rotatable piece to be
spaced from said locking sleeve, thereby enabling rotation of said
rotatable piece and said drive stem with respect to said
housing.
12. The apparatus of claim 11, including a holder for said
container, said holder including means for rotating said locking
device between said locked position and said unlocked position.
13. The apparatus of claim 12, including means for securing said
holder to said locking device while said locking device is in said
locked position.
14. The apparatus of claim 11, including means for locking said
locking device in said locked position.
15. The apparatus of claim 10, wherein said rotatable piece
includes a first set of ratchet teeth and said locking sleeve
includes a second set of ratchet teeth, wherein said first set of
ratchet teeth are in engagement with said second set of ratchet
teeth upon engagement with one another.
16. An apparatus for effecting delivery of an injectable product,
comprising:
a housing;
a cartridge received in said housing for containing and sealing an
injectable product therein, said cartridge including an exit end
and a piston axially movable in said cartridge to define an axis of
ejection of the injectable product from said cartridge;
a manually adjustable dosage metering mechanism rotatably disposed
in said housing for enabling a user to selectively set a dosage of
the injectable product to be delivered without effecting delivery
of the injectable product from said cartridge, said dosage metering
mechanism including a dial having a first stop member, wherein said
housing includes a second stop member, said first stop member
engageable with said second stop member to limit rotation of said
dial to less than 360.degree. to thereby establish a-maximum dosage
setting; and
a delivery mechanism for engaging and axially advancing said piston
a distance sufficient to cause said set dosage to be delivered out
of said cartridge, said delivery mechanism including a hand
operated actuator.
17. A medication dispensing device for effecting the simultaneous
delivery of two injectable products, comprising:
a housing;
a first cartridge received in said housing and containing and
sealing a first injectable product therein, said first cartridge
having a first exit end and including a first piston therein;
a second cartridge received in said housing and containing and
sealing a second injectable product therein, said second cartridge
having a second exit end and including a second piston therein;
a first dosage metering mechanism disposed in said housing and
including a first dosage adjuster coupled to a first
plunger-engageable member such that adjustment of said first dosage
adjuster establishes a first set dosage of injectable product to be
delivered;
a second dosage metering mechanism disposed in said housing and
including a second dosage adjuster coupled to a second
plunger-engageable member such that upon adjustment of said second
dosage adjuster such that adjustment of said second dosage adjuster
establishes a second distance with respect to said housing to
establish a second set dosage of injectable product to be
delivered;
a manifold secured to said first and second exit of said first and
second cartridges, respectively, for enabling the mixing of said
first and second set dosages of said first and second injectable
products within said manifold upon delivery from said respective
cartridges into said manifold, said manifold being in fluid
communication with said first and second cartridges and containing
a common exit for enabling the mixed injectable product to be
delivered to a user; and
a drive mechanism coupled to said first and second
plunger-engageable members for simultaneously axially advancing
said first and second members a distance sufficient to engage and
axially advance said first and second pistons, respectively, to
effect simultaneous delivery of said first and second set dosages
into said manifold and out through said common exit, said drive
mechanism moveable to axially retract said first and second
plunger-engagement members away from said respective first and
second pistons after said delivery of said mixed injectable
product.
18. The dispensing device of claim 17, wherein said first dosage
metering mechanism is coupled to said first plunger-engageable
member such that upon adjustment of said first dosage adjuster,
said first member is axially advanceable a first distance with
respect to said housing to establish said first set dosage of
injectable product to be delivered without effecting delivery of
the first injectable product and said second dosage metering
mechanism is coupled to said second plunger-engageable member such
that upon adjustment of said second dosage adjuster, said second
member is axially advanceable a second distance with respect to
said housing to establish said second set dosage of injectable
product to be delivered without effecting delivery of the second
injectable product.
19. The dispensing device of claim 17, wherein said drive mechanism
includes a carrier, wherein said first and second
plunger-engageable members are secured to said carrier and axially
movable therewith, said carrier being axially advanceable upon
actuation of said injector mechanism to simultaneously advance said
members to effect simultaneous delivery of said first and second
set dosages.
20. The dispensing device of claim 17, wherein the axial
advancement of said first and second pistons in said first and
second cartridges, respectively, defines a first axis of delivery
and a second axis of delivery, respectively, said first and second
axes of delivery being generally parallel to one another, wherein
said dispensing device includes a hand-operated actuator movable in
a direction transverse to said axes of delivery to effect delivery
of the mixed injectable product.
21. The dispensing device of claim 17, wherein said drive mechanism
operates independently of said first and second metering
mechanisms.
22. The dispensing device of claim 17, wherein said first and
second dosage adjustors are rotatable to set said first and second
dosages.
23. The dispensing device of claim 22, wherein said first and
second dosage adjusters are rotatable in both a clockwise direction
and a counterclockwise direction thereby enabling each of said
respective first and second members to be translated axially
forwardly and rearwardly to enable a user to selectively increase
and decrease said first and second set dosages prior to actuating
said injector mechanism.
24. The dispensing device of claim 17, wherein said first and
second plunger-engageable members are leadscrews coupled to said
respective first and second dosage metering mechanisms in such a
manner that adjustment of each said respective dosage adjustor
causes said respective leadscrew to translate axially in a
non-rotary manner within said housing.
25. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a container mounted within said housing and including a piston, an
exit and an injectable product between said piston and said
exit;
a drive stem disposed in said housing and drivingly coupled to said
piston;
a drive assembly mounted to said housing and axially movable in
said housing between a dose-setting position and an injection
position for moving said drive stem to drive said piston within
said container, said drive assembly including a first ratchet
element; and
a dose setting assembly including a second ratchet element coupled
to said first ratchet element to establish a set dosage of
injectable product to be delivered, said dose setting assembly
including an indicator element being movable from a zero dose
reference position against a biasing force to a specific dose
reference position upon the setting of a desired dose to be
delivered, said first ratchet element being in engagement with said
second ratchet element to maintain said indicator element in said
specific dose position while said drive assembly is in said
dose-setting position, said first ratchet element being movable out
of engagement with said second ratchet element upon movement of
said drive assembly from said dose-setting position to said
injection position, thereby enabling said indicator element to be
automatically biased by said biasing force back to its zero dose
reference position.
26. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a container mounted to said housing and including a piston, an exit
and an injectable product between said piston and said exit;
an internally threaded nut disposed in said housing and rotatable
with respect to said housing, and an externally threaded leadscrew
disposed in said nut and drivingly coupled to said plunger;
means secured to said leadscrew for restraining said leadscrew
against rotation upon rotation of said nut so that rotation of said
nut causes translation of said leadscrew;
a drive assembly mounted to said housing and axially movable in
said housing between a pre-injection position and a post-injection
position for moving said leadscrew to drive said piston within said
container, said drive assembly including a clutch element secured
to said nut for rotation therewith, said clutch element including a
first ratchet element, said clutch element, nut, and leadscrew
being axially movable between said pre-injection position and said
post-injection position; and
a dose setting assembly coupled to said drive assembly and
comprising a rotatable element having a dose setting knob and a
rotatable second ratchet element engageable with said first ratchet
element while said drive assembly is in said pre-injection position
so that rotation of said knob results in rotation of said nut, said
rotatable element being rotatable against the force of a spring
from an initial radial position to a selective final radial
position for selectively advancing said leadscrew to set the dosage
of injectable product to be delivered, said first ratchet element
being spaced from said second ratchet element while said drive
assembly is in said post-injection position, whereby said spring
biases said rotatable element from said final radial position to
said initial radial position upon movement of said drive assembly
from said pre-injection position to said post-injection
position.
27. The apparatus of claim 26, wherein said piston is axially
movable in said container toward said exit to define an axis of
ejection of said injectable product, wherein said drive assembly
includes an actuator movable in a direction transverse to said axis
of ejection for moving said drive assembly between said
pre-injection position to said post-injection position.
28. The apparatus of claim 26, wherein said rotatable member
includes a plurality of numerals spaced about said rotatable
member, wherein said housing includes an opening therein and said
rotatable member is arranged in said housing such that a numeral
appears in said opening, thereby indicating to the user the number
of dosage units constituting said set dosage.
29. The apparatus of claim 28, wherein the numeral 0 appears in
said opening while said rotatable member is in its initial radial
position.
30. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a container mounted to said housing and including a piston, an exit
and an injectable product between said piston and said exit;
piston-engagement means disposed in said housing for drivingly
engaging said piston;
drive means mounted to said housing for moving said
piston-engagement means between a pre-injection axial position and
a post-injection axial position, with respect to said housing, to
drive said piston within said container, said drive means including
a first ratchet element, and a nut means coupled to said
piston-engagement means for rotation with respect to said
piston-engagement means, wherein relative rotation between said nut
means and said piston-engagement means controls the amount of
telescopic extension of said piston-engagement means from said nut
means to establish a set dosage of injectable product to be
delivered, said piston-engagement means being axially movable with
said nut means between said pre-injection position and said
post-injection position; and
dose setting means for setting a dosage of injectable product to be
delivered, said dose setting means coupled to said drive means and
comprising a rotatable element including a dose setting knob and a
second ratchet element engageable with said first element while
said drive means is in said pre-injection position, wherein said
dose setting knob is coupled to said nut means while said
piston-engagement means is in said pre-injection position so that
rotation of said knob with respect to said housing results in
rotation of said nut means, said rotatable element being rotatable
against the force of a spring means from an initial radial position
to a selective final radial position for selectively advancing said
piston-engagement means to set the dosage of injectable product to
be delivered, said first ratchet element being spaced from said
second ratchet element while said piston-engagement means is in
said post-injection position, whereby said spring means biases said
rotatable element from said final radial position to said initial
radial position upon movement of said piston-engagement means from
said pre-injection position to said post-injection position.
31. The apparatus of claim 30, wherein said piston is axially
movable in said container toward said exit to define an axis of
ejection of said injectable product, wherein said drive means
includes an actuator movable in a direction transverse to said axis
of ejection for moving said piston-engagement means between said
pre-injection position to said post-injection position.
32. The apparatus of claim 30, wherein said rotatable member
includes a plurality of numerals spaced about said rotatable
member, wherein said housing includes an opening therein and said
rotatable member is arranged in said housing such that a numeral
appears in said opening, thereby indicating to the user the number
of dosage units constituting said set dosage.
33. The apparatus of claim 32, wherein the numeral 0 appears in
said opening while said rotatable member is in its initial radial
position.
34. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a container received in said housing and including a piston, an
exit and an injectable product between said piston and said
exit;
a drive stem disposed in said housing and drivingly coupled to said
piston; and
a drive assembly mounted to said housing and axially movable in
said housing for moving said drive stem to drive said piston within
said container;
wherein a locking mechanism is engageable with said drive stem and
configured to restrict rotation of said drive stem with respect to
said housing, said locking mechanism being in engagement with said
drive stem while said container is securely mounted in said housing
to prevent rotation of said drive stem with respect to said
housing, said locking mechanism being automatically disengaged from
said drive stem upon removal of said container from said housing,
thereby permitting said drive stem to be rotated with respect to
said housing.
35. An apparatus for the delivery of an injectable product,
comprising:
a housing having a proximal end and a distal end;
a removable cartridge retainer received in said distal end of said
housing;
a replaceable cartridge received in said cartridge retainer and
including a piston, an exit and an injectable product between said
piston and said exit, said cartridge retainer being removable to
enable said cartridge to be replaced with another cartridge;
a drive stem disposed in said housing and drivingly coupled to said
piston;
a dosage metering mechanism disposed in said housing to establish a
first set dosage of the first injectable product to be delivered;
and
a drive assembly mounted to said housing and axially movable in
said housing for moving said drive stem to drive said piston within
said cartridge;
wherein an automatic lockout mechanism is engageable with said
drive stem and configured to prevent axial movement of said drive
stem toward said proximal end of said housing independent of said
dosage metering mechanism and said drive assembly, said lockout
mechanism being in engagement with said drive stem while said
cartridge retainer is securely mounted in said housing to prevent
said independent axial movement of said drive stem with respect to
said housing, said lockout mechanism being automatically disengaged
from said drive stem upon removal of said cartridge retainer from
said housing, thereby permitting said drive stem to be axially
moved toward the proximal end of said housing independent of said
dosage metering mechanism and drive assembly.
36. The apparatus of claim 35, wherein said automatic lockout
mechanism comprises a pullback key having an opening that generally
matches the shape of said drive stem and is rotatable with said
drive stem, a pullback sleeve that is rotationally fixed with
respect to said housing and engageable with said pullback key, and
a lock key that is rotatable between an unlocked position and a
locked position, wherein in said locked position, said pullback key
is in engagement with said pullback sleeve to prevent rotation of
said pullback key with respect to said housing, and wherein in said
unlocked position, said pullback key is rotatable with respect to
said pullback sleeve, thereby enabling said independent movement of
said drive stem.
37. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a removable cartridge retainer received in said housing;
a replaceable cartridge received in said cartridge retainer and
including a piston, an exit, and an injectable product between said
piston and said exit, said cartridge retainer being removable to
enable said cartridge to be replaced with another cartridge;
a drive stem disposed in said housing and drivingly coupled to said
piston;
a drive assembly mounted to said housing and axially movable in
said housing for moving said drive stem to drive said piston with
said cartridge;
a hand-operated actuator for moving said drive assembly between a
pre-injection position and a post-injection position; and
means for locking said cartridge retainer to said housing while
said drive assembly is in one of said pre-injection and
post-injection positions.
38. The apparatus of claim 37, wherein said cartridge retainer is
locked to said housing while said drive assembly is in said
pre-injection position.
39. The apparatus of claim 37, wherein said means for locking said
container includes a lock key that is rotatable with respect to
said housing while said drive assembly is in said post-injection
position and said lock key is not rotatable with respect to said
housing while said drive assembly is in said pre-injection
position.
40. The apparatus of claim 39, wherein said cartridge retainer is
keyed to said lock key such that said cartridge retainer is
rotatable with said lock key.
41. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a cartridge retainer received in said housing;
a cartridge received in said cartridge retainer and including a
piston, an exit and an injectable product between said piston and
said exit;
a drive stem disposed in said housing and drivingly coupled to said
piston; and
a drive assembly mounted to said housing and axially movable in
said housing for moving said drive stem to drive said piston within
said cartridge;
a hand-operated actuator for moving said drive assembly between a
pre-injection position and a post-injection position;
wherein a rotatable piece is secured to said drive stem for
rotation therewith, and a locking sleeve is disposed about said
drive stem and configured to restrict rotation of said rotatable
piece with respect to said housing, said rotatable piece and said
locking sleeve being biased in unlocked relationship with one
another, said rotatable piece and said locking sleeve being forced
into locked engagement with one another while said retainer is
mounted to said housing to prevent rotation of said rotatable piece
and said drive stem with respect to said housing, said rotatable
piece and said locking sleeve being automatically disengaged from
one another upon removal of said retainer from said housing,
thereby permitting said rotatable piece and said drive stem to be
rotated with respect to said housing.
42. The apparatus of claim 41, wherein a spring is positioned in
said housing with respect to said rotatable piece and said locking
means to apply a biasing force sufficient to separate a first
locking element of said rotatable piece from a second locking
element of said locking means, said spring means being positioned
in said housing such that upon said container being secured to said
housing end, said spring means is compressed sufficiently to permit
said rotatable piece to lockingly engage with said locking
means.
43. The apparatus of claim 41, wherein said rotatable piece
includes a first set of ratchet teeth and said locking means
includes a second set of ratchet teeth, wherein said first set of
ratchet teeth are in engagement with said second set of ratchet
teeth while said container is mounted to said housing.
44. The apparatus of claim 41, wherein said plunger-engagement
means is moveable axially from said housing end and toward a second
and opposite housing end upon said container being removed from
said housing.
45. An apparatus for the delivery of an injectable product,
comprising:
a housing;
a container received in said housing and including a plunger, an
exit and an injectable product between said plunger and said
exit;
plunger-engagement means disposed in said housing for drivingly
engaging said plunger; and
drive means mounted to said housing and axially movable in said
housing for moving said plunger-engagement means to drive said
plunger within said container,
wherein a rotatable piece is secured to said drive stem for
rotation therewith, and a locking means is disposed about said
drive stem and configured to restrict rotation of said rotatable
piece with respect to said housing, said rotatable piece and said
locking means biased in unlocked relationship with one another,
said rotatable piece and said locking means being forced into
locked engagement with one another while said container is mounted
to said housing to prevent rotation of said rotatable piece and
said plunger-engagement means with respect to said housing, said
rotatable piece and said locking means being automatically
disengaged from one another upon removal of said container from
said housing, thereby permitting said rotatable piece and said
plunger-engagement means to be rotated with respect to said
housing.
46. A method of delivering a selected dosage of injectable product,
the method comprising the steps of:
moving a hand-operated actuator to a pre-injection position;
rotating a knob extending from an injector housing to set a dosage
of injectable product to be delivered out of a container mounted to
an end of the housing, wherein the injectable product is in the
container between a piston and an exit end of the container,
wherein movement of the piston toward the exit end defines an axis
of ejection of the injectable product from the container; and
continuously moving the actuator in a direction transverse to the
axis of ejection from the pre-injection position to a
post-injection position to move the piston and effect delivery of
the injectable product.
47. The method of claim 46, wherein the step of continuously moving
the actuator includes moving the actuator through a given angular
range of motion, wherein incremental movement of the actuator
results in a corresponding incremental axial advancement of a drive
assembly which carries a piston-engaging stem.
48. The method of claim 46, wherein the step of rotating includes
rotating the knob in a first rotational direction to increase the
set dosage and then in a second and opposite rotational direction
in order to decrease the set dosage.
49. The method of claim 46, wherein movement of the actuator causes
the knob to be rotated back to an initial rotational position.
50. The method of claim 46, wherein the step of moving the actuator
to the pre-injection position causes the piston-engaging stem to
axially retract off of the piston.
51. A method of delivering a selected dosage of mixed injectable
product, the method comprising the steps of:
moving a hand-operated actuator to a pre-injection position;
rotating a first knob of a first dosage metering mechanism disposed
in an injector housing to set a first set dosage of first
injectable product to be delivered out of a first container mounted
in the housing, wherein the first injectable product is in the
first container between a first piston and a first exit end of the
first container, wherein the first piston is movable toward the
first exit end along a first axis of ejection of the first
injectable product from the first container;
rotating a second knob of a second dosage metering mechanism
disposed in the injector housing to set a second set dosage of
second injectable product to be delivered out of a second container
mounted in the housing, wherein the second injectable product is in
the second container between a second piston and a second exit end
of the second container, wherein the second plunger is movable
toward the second exit end along a second axis of ejection of the
second injectable product from the second container, the second
axis being generally parallel to the first axis; and
moving the actuator in a direction transverse to the first and
second axes of ejection to a post-injection position to
simultaneously axially advance first and second piston-engagement
members in the housing to axially advance the first and second
pistons, respectively, to effect simultaneous delivery of the first
and second set dosages into a manifold attached to the first and
second exit ends of the first and second containers and out through
a needle extending from the manifold.
52. The method of claim 51, wherein the step of moving the actuator
includes moving the actuator through a given angular range of
motion, wherein incremental movement of the actuator results in a
corresponding incremental axial advancement of a drive assembly
which carries the first and second members.
53. The method of claim 51, wherein the step of rotating includes
rotating at least one of the first and second knobs in a first
rotational direction to increase the respective set dosage and then
in a second and opposite rotational direction in order to decrease
the respective set dosage.
54. The method of claim 51, wherein movement of the actuator causes
at least one of the first and second knobs to be rotated back to an
initial rotational position.
55. A method of delivering a selected dosage of injectable product,
wherein the injectable product is in a cartridge between a piston
and an exit end of the cartridge, the cartridge being replaceable
and received in a removable cartridge retainer, the cartridge
retainer being received in an injector housing and removable to
enable the cartridge to be replaced with another cartridge, the
method comprising the steps of:
moving a hand-operated mechanism to a pre-injection position,
thereby automatically locking the cartridge retainer to the
housing;
actuating a dosage metering mechanism disposed in the injector
housing to set a dosage of injectable product to be delivered out
of the cartridge; and
moving the hand-operated mechanism from the pre-injection position
to a post-injection position to effect delivery of the injectable
product, thereby automatically unlocking the cartridge retainer
from the housing to permit the cartridge retainer to be removed
from the housing.
56. The method of claim 55, wherein the step of moving the
hand-operated mechanism to the pre-injection position automatically
prevents the cartridge retainer from being rotatable with respect
to the housing, and wherein the step of moving the hand-operated
mechanism to the post-injection position automatically permits the
cartridge retainer to be rotated with respect to the housing.
57. The method of claim 55, wherein movement of the hand-operated
mechanism from the pre-injection position to the post-injection
position causes the dosage metering mechanism to be automatically
rotated back to an initial rotational position.
58. The method of claim 55, wherein movement of the hand-operated
mechanism from the pre-injection position to the post-injection
position causes the dosage metering mechanism to be decoupled from
a drive mechanism which effects delivery of the injectable
product.
59. The method of claim 55, including the step of removing the
cartridge retainer and cartridge from the housing while the
hand-operated mechanism is in the post-injection position.
60. The method of claim 59, including the step of inserting a
second cartridge into the cartridge retainer.
61. The method of claim 60, including the step of attaching the
cartridge retainer to the housing while the hand-operated mechanism
is in the post-injection position.
62. The method of claim 61, wherein the step of attaching the
cartridge retainer to the housing includes the steps of causing a
second piston of the second cartridge to engage a piston-engagement
member in the injector housing, forcing the piston-engagement
member to translate axially within the housing toward the
hand-operated member, and rotating the cartridge retainer within
the housing to secure the cartridge retainer within the
housing.
63. A method of delivering a selected dosage of injectable product,
the method comprising the steps of:
rotating a cartridge retainer into a locked position with respect
to an injector housing, thereby automatically causing a
piston-engagement stem within the housing to become locked against
rotation with respect to the housing;
setting a dosage of injectable product to be delivered out of a
cartridge of liquid medication housed in the cartridge retainer and
containing the liquid medication between a movable piston and an
exit;
moving a hand-operated actuator to effect nonrotating axial
advancement of the piston-engagement stem to effect delivery of the
set dosage of injectable product out of the exit end;
removing the cartridge retainer and cartridge from the housing
thereby automatically enabling the piston-engagement stem to be
rotatable with respect to the housing; and
causing the piston-engagement stem to rotate with respect to the
housing and simultaneously axially move toward an opposite end of
the housing.
64. The method of claim 63, including the steps of inserting a
second cartridge into the cartridge retainer and attaching the
cartridge retainer to the housing, thereby automatically causing
the piston-engaging stem to axially move toward the opposite end of
the housing and then become locked against rotation with respect to
the housing upon rotation of the cartridge retainer onto the
housing.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to devices for injecting
two or more medications simultaneously and, more particularly, to a
medication injection device having improved dose setting and
injection capabilities.
It is medically desirable in the treatment of certain conditions of
the human body to administer two or more types of medication
simultaneously. The treatment of diabetes is one such example.
Under certain conditions, it is desirable to simultaneously deliver
two types of insulin: fast acting insulin and an intermediate
acting insulin, such as isophene insulin, which takes effect more
slowly but for a longer period of time. Also, a longer acting type
of insulin called ultralente is available. In order to most
accurately simulate the natural glucose curve of the body, the
insulin user injects different ratios or combinations of these
insulins several times daily.
In order to achieve such injection capability, there have been
developed injection devices in which separate cartridges of a
desired medication are housed. It is desirable that both
medications be delivered to a patient through a single needle
instead of two or more needles. Therefore, such injection devices
have a manifold assembly that enables the medications to be mixed
together prior to injection.
One such type of injection device is proposed in U.S. Pat. No.
5,253,785. This patent asserts a dispenser for injecting variable
mixed proportions of NPH and regular human insulin. The dosages of
each medication are set prior to delivery. Dosing is achieved by
rotating a dose knob to translate a dosage adjuster to a retracted
position. The second dosage knob is adjusted in a similar manner.
The dosage adjusters are coupled to a sliding body. After the
appropriate dosages are set, the sliding body is forced forwardly,
which causes the drive stems to translate forwardly. Since the
drive stems are connected to pistons within each medication
cartridge, movement of the drive stems drives the pistons forward
to expel liquid from the cartridges. The forward stroke of the
sliding body is limited by the distance set by the dosage
adjusters.
Another type of dual medication injection device is proposed in PCT
International Application No. PCT/US93/11044. In this device,
dosage knobs are rotated to translate the dosage adjusters to their
retracted positions. Movement of the dosage adjusters compresses
springs, which engage flanges on the adjusters. This compression
preloads the drive stems so that moving the needle assembly from
the predelivery position to the delivery position causes the
dosages of pharmaceutical to be automatically driven from the
pharmaceutical chambers, past the check valves and through the
doubled ended needle cannula.
SUMMARY OF THE INVENTION
The present invention provides in one embodiment thereof a
hand-held liquid medication delivery device capable of
simultaneously delivering at least two medication products. The
medication products are housed in variable volume containers or
cartridges within the mechanism housing of the device. Each
cartridge contains a liquid medication between a piston and an exit
end. The medication delivery device includes independent
bidirectional dosage metering mechanisms for permitting a variable
dosage amount of each liquid medication to be set prior to
delivery. A delivery mechanism is provided for simultaneously
axially advancing piston-engaging stems to engage and axially
advance the pistons in the cartridges to effect delivery of the
medications into a manifold at the distal end of the device. The
medications are mixed within a valved mixing chamber in the
manifold and the mixed product is delivered through a single
delivery needle extending from the manifold. A lock and pullback
mechanism incorporated into the delivery device automatically
prevents the cartridges from being removed from the housing while
the injection actuator is in a metering or pre-injection position.
The cartridges are replaced after the contents thereof have been
exhausted.
In one embodiment, the present invention provides a medication
delivery device having a dosage metering mechanism for setting a
dosage of liquid medication to be delivered prior to injection. The
dosage metering mechanism includes a knob and indicator dial which
function as a single component that is rotatable with respect to
the mechanism housing. The mechanism includes an indicator bearing
that is locked to the housing. A torsion spring is loaded between
the knob and the bearing. The knob/indicator dial is coupled to a
movable element on the drive mechanism. Upon rotation of the knob
to set a dosage of liquid medication to be delivered the spring is
tensed, and a dosage is indicated by a numeral on the indicator
dial appearing in a window in the housing. Upon actuating the
delivery mechanism, the movable element is moved out of engagement
with knob/indicator dial, thereby enabling the spring to
automatically rotate the indicator dial back to a zero dose
position.
In one embodiment of the present invention, a multi-component
medication delivery device is provided having a drive mechanism for
simultaneously delivering a set dosage of each injectable product.
An elongated tubular element or nut and a drive stem is associated
with each liquid medication to be delivered. A driver or carrier is
secured to each nut. Each driver is pivotally secured to a
hand-operated actuator via side plates. Upon a single stroke of the
actuator from its pre-injection position to its post-injection
position, each of the drivers are simultaneously driven forwardly
carrying the nut and drive stem therealong. The drive stems engage
and axially advance their respective pistons to force the
respective set dosages of liquid medications into the manifold and
out through the delivery needle. Upon movement of the actuator back
to its pre-injection position, the drive stems are moved off of
their respective pistons back into a retracted position within the
housing.
The present invention further provides in one form thereof a liquid
medication delivery device having a lock and pullback mechanism
which prevents the drive stems or leadscrews from rotating during
metering and injection. This mechanism also prevents the cartridges
from being changed during metering and injection. The lock and
pullback mechanism includes a pullback key having an opening
matching the shape of the leadscrew and being rotatable with the
leadscrew, a pullback sleeve which is engageable and disengageable
with the pullback key, a lock key which is rotatable with respect
to the pullback sleeve, and a spring-loaded snap lock. While the
actuator is in its pre-injection or dose-setting position, the lock
key is locked in a first rotational position. In this first
rotational position, the lock key forces the pullback key and the
pullback sleeve into engagement with one another. Since the
pullback sleeve is locked against rotation with respect to the
housing, the pullback key and leadscrew are prevented from being
able to rotate with respect to the housing. Upon injection, the
drive nut engages and slightly axially advances the pullback sleeve
and the lock key with respect to the housing. This moves the
fingers of the lock key out of radial engagement with interfering
ribs on the inner surface of the housing to enable the lock key to
be rotated between a first rotational position and a second
rotational position. Upon rotation of the lock key to its second
position, the lock key moves slightly axially with respect to the
pullback sleeve. This permits the pullback key to become disengaged
from the pullback sleeve to allow the pullback key and leadscrew to
rotate with respect to the pullback sleeve.
A cartridge retainer containing a cartridge of liquid medication is
received within the nosepiece of the housing and rotatable within
the nosepiece between a locked rotational position, in which the
retainer cannot be removed from the nosepiece, and an unlocked
rotational position in which the retainer can be removed from the
nosepiece. The retainer includes tabs that are keyed for rotation
with the lock key. Thus, the retainer is locked against rotation in
its locked position while the actuator is in its pre-injection
position, and the retainer is rotatable with the lock key to its
unlocked position while the actuator is in its post-injection
position, thereby enabling the retainer and spent cartridge to be
removed and replaced with a new variable volume cartridge. Upon
securing the new cartridge onto the housing, the piston of the new
cartridge engages and axially spins the leadscrew back to its home
position. This is possible since the leadscrew can rotate with
respect to the housing while the actuator is in its post-injection
position.
In one embodiment of the present invention, a multi-component
medication delivery device is provided having a drive mechanism for
simultaneously delivering a selectively set dosage of each
injectable product. The device comprises a mechanism housing and a
plurality of variable volume cartridges containing the medication
and disposed within the housing, wherein each cartridge defines an
axis of delivery of the medication from its respective cartridge.
An elongated tubular element or nut and a drive stem is associated
with each cartridge. A driver or carrier is secured to each nut.
Each driver is pivotally secured to a hand-operated actuator via
side plates. During metering, the actuator is in its "up" position,
and each leadscrew is advanced a desired distance to set a desired
dosage of product to be delivered. After the desired dosages have
been set, the actuator is moved in a direction transverse to the
axes of delivery, toward the housing, and into its "down" position.
Upon this single stroke, each of the drivers are simultaneously
driven forwardly carrying the nut and drive stem therealong. The
drive stems engage and axially advance their respective pistons to
force the respective set dosages of liquid medications into the
manifold and out through the delivery needle. As the actuator moves
into its "down" position, a groove in the actuator receives a tab
on the housing resulting in an audible "click" to indicate an end
of dose to the user.
An advantage of the present invention is that the device enables a
user to independently set each dosage of product to be
delivered.
Another advantage of the present invention is that the device
enables bidirectional metering of each dosage to be set.
Another advantage of the present invention is that the device is
capable of indicating and locking out metering of an insufficient
remaining volume of liquid medication in a cartridge.
Another advantage of the present invention is that the device
provides a tactile, visual, and auditory feedback during
metering.
Another advantage of the present invention is that the device
provides both a visual and auditory indication of an end of
dose.
Another advantage of the present invention is that the metering
mechanism automatically resets upon injection, thereby eliminating
the need to manually reset the indicator dial back to zero prior to
subsequent metering.
Another advantage of the present invention is that metering can be
achieved only while the actuator is in the "wing up" or
pre-injection position, thereby ensuring proper metering.
Another advantage of the present invention is that the device
automatically prevents a user from attempting to change cartridges
while the device is in its metering or pre-injection position,
thereby maintaining dosing accuracy.
Another advantage of the present invention is that the leadscrew is
automatically unlocked upon a cartridge change, thereby enabling
the leadscrew to spin freely back to its home position upon
inserting a new cartridge into the housing.
Other advantages will become apparent in the detailed description
of a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an embodiment of a medication
dispensing device in accordance with the present invention, wherein
the wing is shown in its "up" position;
FIG. 2 is an exploded view of the device of FIG. 1;
FIG. 3 is an enlarged longitudinal sectional view of the medication
dispensing device of FIG. 1, wherein the actuating wing is in the
"up" position;
FIG. 4 is a view of FIG. 3, showing the leadscrews advanced
indicating a set dosage has been established;
FIG. 5 is a view of FIG. 3, particularly showing the dispensing
device immediately after an injection has taken place;
FIG. 6 is an enlarged isolated perspective view of the metering
mechanism of the device of FIG. 1;
FIG. 7 is a sectional view of the engagement between the rotatable
clutch member and the elongated nut;
FIG. 8 is an isolated elevational end view of the nut and the
driver, particularly showing the ratchet teeth of the nut in
engagement with the corresponding ratchet teeth of the driver;
FIG. 9 is a sectional view showing the externally threaded
leadscrew in engagement with the internally threaded portion of the
nut;
FIG. 10 is a view of FIG. 9, particularly showing the leadscrew
fully advanced through the nut;
FIG. 11 is an enlarged sectional view of the assembled lock and
pullback mechanism of the device of FIG. 1;
FIG. 12 is an enlarged sectional view of the lock and pullback
mechanism as shown in FIG. 11, taken along line 12--12 in FIG.
11;
FIG. 13 is a sectional view of the indicator dial in engagement
with the maximum dosage splines in the injection pen housing;
FIG. 14 is a sectional view of the wing mechanism of the dispensing
device in engagement with the housing in its wing down
position;
FIG. 15 is an exploded perspective view of the lock and pullback
mechanism;
FIG. 16 is a sectional view of the assembled lock and pullback
mechanism particularly showing the lock key within the groove of
the pullback sleeve, thereby preventing rotation of the key with
respect to the sleeve;
FIG. 17 is a view of the lock and pullback mechanism of FIG. 16,
particularly showing the driver at the end of dose thereby
automatically permitting rotation of the lock key with respect to
the housing;
FIG. 18 is a sectional view of the interference fit between the
small flanges of the lock key and the legs of the lock snap;
FIG. 19 shows the legs of the lock snap in engagement with the
small flanges;
FIG. 20 is a view similar to FIG. 19, showing the lock snap out of
engagement with the small flanges of the lock key to permit
rotation of the lock key with respect to the pullback sleeve;
FIG. 21 is a sectional view of the cartridge retainers in the
distal housing of the medication dispensing device of FIG. 1,
particularly showing the retainers in an unlocked state;
FIG. 22 is a view of FIG. 21, except that the cartridge retainers
have been rotated to their locked positions; and
FIGS. 23A-23D are a series of elevational views of the medication
dispensing device of FIG. 1 showing the manifold being removed
(FIG. 23A), the cartridge retainers being unlocked and removed from
the housing (FIG. 23B), new cartridge retainers being inserted into
the housing (FIG. 23C) and the manifold being replaced onto the
distal end of the housing (FIG. 23D).
FIG. 24A is an isolated view, in partial section, of the wing and
driver mechanism of the device of FIG. 1, showing the wing in its
"up" position.
FIG. 24B is a view of FIG. 24, except that the wing is in its
"down" position.
DESCRIPTION OF A PREFERRED EMBODIMENT
In an embodiment of the invention as shown in the drawings, and in
particular by referring to FIGS. 1 and 2, there is shown a
medication dispensing device 40 for dispensing two different liquid
medications as a mixed product through a single needle 41. The
injection device includes a mechanism housing 42 (FIG. 2) and a
nosepiece 44. Mechanism housing 42 is contained in housing covers
46 and 48. Both mechanism housing 42 and nosepiece 44 are clear
plastic materials made of ABS resins or polycarbonates. In one
embodiment, mechanism housing 42 and nosepiece 44 are
ultrasonically welded to one another. In one method, the mechanism
housing is placed in a nest supported by the back side of the ribs
of the nosepiece, and a far field weld is performed with a horn on
the top of the nosepiece. In another method, the mechanism housing
and nosepiece are spring loaded together, and weld energy is
injected orthogonally to the pressure direction at the semicircular
ribs of the nosepiece.
Mechanism housing 42 comprises two parallel tubular components 50
and 54 for housing the individual components of device 40.
Nosepiece 44 is also in the form of two parallel tubular components
52 and 56. Together, tubular components 50 and 52 form a first
tubular member and tubular components 54 and 56 form a second
tubular member. Although two parallel tubular members are shown in
the drawings, it is possible that additional tubular members may be
provided to meter and deliver three or more liquid medications from
a single delivery device. Additional features of mechanism housing
42 and nosepiece 44 shall be described infra.
As shown in the drawings, dispensing device 40 contains two
independent dosage metering mechanisms, a drive mechanism for
simultaneously driving the pistons of the cartridges for dual
medication injection, and two separate lock and pullback
mechanisms. A detailed discussion of each mechanism follows. The
two metering mechanisms shown in FIGS. 3-5 are substantially
identical except for certain differences illustrated in FIG. 13.
Likewise, the drive mechanism and the lock and pullback mechanisms
within each tubular member are substantially identical to one
another. Therefore, identical components in each of the two
parallel tubular members formed by mechanism housing 42 and
nosepiece 44 are given identical reference numerals.
Referring to FIGS. 2-6, a dosage metering mechanism 58 is shown.
Although a single metering mechanism shall be discussed herein, it
is understood that delivery mechanism 40 includes two such metering
mechanisms. Metering mechanism 58 comprises a knob 60, a torsion
spring 62, an indicator bearing 64, an indicator dial 66, and a
clutch indicator 68. Indicator bearing 64 is a thin, molded plastic
annular ring with hook-shaped protrusions 70 extending radially
away from its outer circumference. As shown in FIG. 3, protrusions
70 securely fit within openings 71 (FIG. 2) formed at the proximal
end of mechanism housing 42. Thus, indicator bearing 64 is fixed
both rotationally and axially to mechanism housing 42. For purposes
of this application, the term "proximal" shall designate a relative
axial position toward the knob end of delivery mechanism 40, and
the term "distal" shall designate a relative axial position toward
the delivery needle end of delivery mechanism 40.
As shown in FIGS. 2 and 3, indicator dial 66 is an elongate molded
plastic cylinder that fits coaxially within tubular region 54 of
mechanism housing 42. Knob 60 is a molded plastic cylinder with a
closed proximal end and an open distal end. The proximal end of
indicator dial 66 snaps into an annular groove (not shown) molded
within knob 60 so that indicator dial 66 and knob 60 constitute a
single rotatable component. Torsion spring 62 is coupled at one end
72 to indicator dial 66 and at the opposite end 74 to indicator
bearing 64. Knob 60 and indicator dial 66 are rotated against the
biasing force of torsion spring 2. In the absence of another force
to retain knob 60 and indicator dial 66 in a given radial position,
torsion spring 62 will return knob 60 and indicator dial 66 to a
given initial rotational position, also known as the zero dose
position.
As shown in FIGS. 6 and 13, indicator dial 66 further includes an
axially extending spline 76 which rotates within a mating slot 78
on the inside surface of tubular region 54 to confine the
rotational travel of indicator dial 66 to less than 360 degrees.
This serves to limit the dosage that a user can set for any single
injection. In FIG. 13, there is shown an indicator dial 66' which
is identical to indicator dial 66 except that spline 76' is of a
greater width than spline 76. Thus, the maximum dosage that can be
set with indicator dial 66' is less than that which can be set with
indicator dial 66.
Referring to FIG. 6, the distal portion of indicator dial 66 has a
series of numerals 80 printed about the circumference thereof. An
opening or window 82 in the wall of tubular region 54 and a
corresponding opening 84 in housing cover 48 allows a user to view
at least one of numerals 80. A lens 86 (FIG. 2) is provided in
opening 84 to magnify the visible numeral 80 as desired. The
numerals represent different set dosages of liquid medication to be
delivered in international recognized units. As the knob 60 and
indicator dial 66 are rotated, different numerals 80 appear
centered in openings 82 and 84. The reference numeral "0" is
present when knob 60 and indicator dial 66 are in their initial
position set by torsion spring 62. The metering mechanism
interfaces with the drive mechanism as discussed infra.
Referring to FIG. 2, the components of the drive mechanism are
shown. The drive mechanism includes an elongated molded plastic,
hollow cylindrical drive nut 88. Nut 88 includes an internally
tapped bore extending therethrough. As shown in FIGS. 9 and 10, the
distal portion 90 of nut 88 includes internal threads 92. These
threads may be any desired helix, such as a 28-45 degree helix. The
remaining interior surface of the bore of nut 88 constitutes a
relatively smooth surface 94. A shoulder or ledge 96 is formed at
the intersection between smooth interior surface 94 and internally
threaded surface 92. Referring to FIG. 7 the outer surface of nut
88 includes a plurality of axially extending splines 98 and 99.
These splines engage corresponding recesses 103 and 104 in
indicator clutch 68, thereby locking nut 88 to indicator clutch 68.
Referring to FIG. 8, the distal end of nut 88 includes an enlarged
diameter end 100 including ratchet teeth 102. Referring to FIGS.
2-5, a drive spring 108 is disposed between the distal end of drive
locknut 106 and the distal end 110 formed in the interior of
indicator clutch 68. An indicator washer 112 is secured to
indicator clutch 68, and an indicator spring 114 is disposed
between washer 112 and tubular region 54 of housing 42.
An elongated metal externally threaded leadscrew 118 is adapted to
threadingly engage the interior threaded surface 92 of drive nut
88. Leadscrew 118, while generally cylindrical, has two
diametrically opposite parallel flat surfaces 126 (FIG. 2)
extending along its entire length. Leadscrew 118 is longer than
drive nut 88, and when assembled, the proximal end of leadscrew 118
extends beyond the threaded portion of drive nut 88. The proximal
end of leadscrew 118 includes an enlarged diameter portion 120. A
plastic head 122 is slidably snapped onto end piece 124 of
leadscrew 118. Head 122 is rotatably attached to end piece 124 and
is pivotal with respect thereto.
As shown in FIGS. 3-4, the metering mechanism is coupled to the
drive mechanism. Specifically, ratchet teeth 67 of indicator dial
66 are in engagement with ratchet teeth 69 of indicator clutch 68.
Thus, rotation of knob 60 results in rotation of indicator clutch
68. Since the splines 98, 99 of drive nut 88 are keyed to grooves
103, 104 in indicator clutch 68, rotation of indicator clutch 68
results in rotation of nut 88. Leadscrew 118 is locked against
rotation during metering as shall be discussed infra. Since nut 88
is locked to the drive mechanism and cannot move axially with
respect to the housing during metering, rotation of nut 88 causes
axial translation of leadscrew 118 due to the threaded connection
therebetween. After an initial desired dosage has been set, knob 60
may be turned either clockwise or counterclockwise to translate
leadscrew 118 either forward or backward until the desired dosage
is set. This allows a user to change a dosage without wasting the
medication to be delivered.
Referring to FIGS. 9 and 10, a carrier or driver 116 is in constant
engagement with distal end 100 of drive nut 88. As shown in FIGS.
2, 24A and 24B, driver 116 is secured to plates 128 which are
pivotally connected to wing 132 by pins 129 being received in pivot
bores 133. Wing 132 includes a plastic grip 134 which is received
within opening 136 within wing 132, as shown in FIG. 2. Wing 132
includes pivot bores 135, which receive opposite ends of a pivot
pin 137 which extends through opening 139 in housing mechanism 42.
Bores 127 in drivers 116 receive pins 131 of side plates 128.
Referring to FIGS. 24A and 24B, upon movement of wing 132 toward
mechanism housing 42 to its "down" position (FIG. 24B), side plates
128 and 130 are carried forwardly, which carry respective drivers
116 forwardly. Since each driver 116 is adjacent end 100 of nut 88,
movement of driver 116 carries forward nut 88 and leadscrew 118.
Upon movement of wing 132 away from mechanism housing 42 to its
"up" position (FIG. 24A), side plates 128 and 130, driver 116, nut
88 and leadscrew 118 are all retracted.
The lock and pullback mechanism comprises a plastic molded,
generally cylindrical pullback key 138 which has a proximal portion
140 including an opening 142 that corresponds to the shape of
leadscrew 118 and an enlarged distal portion 144 including ratchet
teeth 146. The lock and pullback mechanism further comprises a
generally cylindrical molded pullback sleeve 148 comprising a
proximal hollow cylindrical portion 150 and radially extending
flanges 152. The outer surface of pullback sleeve 148 includes a
spiral groove or track 154. The interior surface of pullback sleeve
148 including a reduced diameter inner surface 156 and an enlarged
inner diameter surface (not shown). The intersection of the inner
surfaces of pullback sleeve 148 form ratchet teeth 158 which are
engageable with ratchet teeth 146 of pullback key 138. The lock and
pullback mechanism further includes a lock key 160, a pullback
spring 162, and a snap lock 164. Lock key 160 comprises a generally
cylindrical portion 166 having grooved openings 168 formed at the
distal end thereof and further having axially extending fingers 170
extending from the opposite end thereof. Fingers 170 include small
cylindrical protrusions 172 that fit within spiral groove 154 of
pullback sleeve 148. Lock key 160 further includes ledges 174
extending radially inwardly from the inner surface of lock key
160.
Snap lock 164 comprises a cylindrical portion 176 and two axially
extending legs 178 having outwardly extending tabs 180. Pullback
spring 162 is disposed between inner ledge 182 of snap lock 164 and
inner radially extending ledges 174 of lock key 160.
The lock and pullback mechanism performs several functions. First,
pullback key 138 interfaces with leadscrew 118 to keep the
leadscrew 118 from turning during metering and injection. Pullback
key 138 is locked from rotation by the engagement of corresponding
teeth from pullback sleeve 148 which, in turn, is constantly
constrained from rotating by its interface with mechanism housing
42. Lock snap 164 and pullback spring 162 take up the variable
position of the end of the glass cartridge. In addition, lock snap
164 holds the lock/pullback mechanism within the mechanism housing.
Lock key 160 provides a lockout for the cartridge retainers so that
the retainers can only be removed and inserted when the wing is in
the "down" position. It is important to lock out cartridge change
in the wing "up" position because for a proper leadscrew reset to
occur, the plunger of the replacing cartridge needs to push the
leadscrew back and the wing must pull the leadscrew off the plunger
by a distance of at least the maximum dosing distance. Pullback
sleeve 148 unloads the pullback key 138 during a cartridge change
such that the leadscrew can spin freely back to its home position.
The lock and pullback mechanism will be described in additional
detail upon a description of the manner of use of device 40.
Referring to FIG. 2, injection device 40 includes cartridges 184,
186 disposed within cartridge retainers 188, 190. Retainers 188,
190 which may be made of a clear plastic material, such as Ektar,
include internal ribs 189, 191 (FIGS. 21-22) to ensure proper
alignment of the cartridges in the retainers. Retainers 188, 190
are secured within the tubular regions 52 and 56 of nosepiece 44 as
discussed infra. Retainer 188 may be of a different size than
retainer 190 so that retainer 188 cannot be inadvertently inserted
into cylindrical tube 56, and vice versa. A manifold assembly 192
is secured to the distal end of cartridge retainers 188 and 190 and
includes a front housing 194, a rear housing 196, and an
elastomeric septum 198 encapsulated therebetween. The manifold
assembly is described in greater detail in U.S. patent application
Ser. No. 08/333,207, filed Nov. 2, 1994, entitled MANIFOLD FOR
INJECTION APPARATUS, which disclosure is incorporated herein by
reference. Needle 41 is secured to front manifold housing 194 via
threaded coupling member 200. Injection device 40 further includes
needle cover 202 and housing cap 204.
In order to set a dosage, wing 132 must be moved in the direction
of arrow 212 to its "up" position, as shown in FIG. 3. This causes
heads 122 of leadscrews 118 to be retracted out of engagement with
pistons 185, 187 of cartridges 184, as shown in FIG. 3. In
addition, movement of wing 132 in the direction of arrow 212
retracts clutch indicator 68 to its proximal position. While in
this position, ratchet teeth 67 of indicator dial 66 are in
engagement with ratchet teeth 69 of indicator clutch 68 so that
rotation of knob 60 and indicator dial 66 results in corresponding
rotation of indicator clutch 68. As indicator clutch 68 is rotated,
internal threads 92 of clutch 68 engage with external threads 119
of leadscrew 118 to cause axial translation of leadscrew 118 toward
piston 185. Leadscrew 118 is prevented from rotating due to ratchet
teeth 146 of pullback key 138 being in locking engagement with
ratchet teeth 158 of pullback sleeve 148. Since pullback sleeve 148
is keyed against rotation with respect to the housing, pullback key
138 and leadscrew 118 likewise cannot rotate with respect to the
housing. As a result, rotation of nut 88 results in the
nonrotational translation of leadscrew 118 toward piston 185, as
shown in FIG. 4.
Rotation of each knob 60 must initially be in the clockwise
direction, as indicated by arrows 214 (FIG. 4) to set a desired
dosage. Initial rotation in the counterclockwise direction is
prevented by the engagement of splines 76, 76' of indicator dials
66, 66' being in engagement with dosage stops 79 formed in tubular
regions 50 and 54 (FIG. 13). Once an initial dosage has been set,
that dosage may be increased or decreased as desired by clockwise
or counterclockwise rotation of knobs 60. FIG. 4 shows leadscrews
118 being advanced a desired axial distance with respect to their
axial positions in FIG. 3, indicating that dosages have been set.
Rotation of knob 60 results in corresponding numerals 80 appearing
in openings 82 and 84 of housings 42 and 48, respectively, to
provide a visual indication of the desired dose. In addition,
rotation of nut 88 results in teeth 102 of end 100 being moved over
teeth 117 of driver 116, resulting in an audible click for each
incremental increase or decrease in the set dosage.
Once the desired dosage of both medications has been set, needle
cover 202 is removed from needle 41, and needle 41 is inserted into
the user. Wing 132 is then grasped and move transversely towards
the housing as shown by arrow 206 in FIG. 5. This results in
drivers 116 moving forward which carry nuts 88 and leadscrews 118
forwardly a predetermined distance resulting in heads 122 engaging
and axially advancing associated pistons 185, 187. This forces
medication through cannulas 208, 210 and into manifold assembly 192
and subsequently out needle 41.
As wing 132 is pushed toward the housing, ratchet teeth 69 of
clutch indicator 68 move out of engagement with ratchet teeth 67 of
indicator dial 66, thereby enabling torsion spring 62 to rotate
knob 60 and clutch indicator 66 to its initial rotational position,
whereby the numeral zero appears through windows 82 and 84 in
housings 42 and 48, respectively. This auto zero feature permits a
user to redial another dose without having to first set the
metering dial to zero.
Referring to FIG. 14, grip piece 134 of wing 132 includes a
downwardly extending boss portion 216 biased in a given axial
position with respect to wing 132 by a spring 218. Boss 216
includes a finger 220 that slides over upstanding tab 222 on
tubular region 50 and fits into place beneath tab 222 in
interfering relationship therewith which holds finger 220 in place.
This locks wing 132 in the "down" position at the end of dose. The
engagement of finger 220 beneath tab 222 results in an audible
click sound, indicating to the user that the complete dosage has
been delivered. Spring 218 biases finger 220 beneath tab 222.
At the end of an injection, end 100 of nut 88 engages and axially
advances pullback sleeve 148, pullback key 138 and lock key 160, as
shown in FIGS. 19 and 20. This moves flanges 152 of pullback sleeve
148 out of engagement with groove 149 in tubular housing region 50.
This also moves protrusion 224 on lock key 160 out of interfering
relationship with extension 226 of tubular region 50. Cartridge
retainer 188 and lock key 160 keyed thereto can now be rotated 90
degrees to move protrusions 172 of lock key 160 within helical
spline 154 of pullback sleeve 148. Such rotation moves lock key 160
and ledges 174 of lock key 160 axially away from pullback key 138
so that ledges 174 no longer engage pullback key 138. This causes
ratchet teeth 146 of pullback key 138 to become disengaged from
ratchet teeth 158 of pullback sleeve 148, thereby enabling pullback
key 138 and hence leadscrew 118 to rotate with respect to pullback
sleeve 148 and mechanism housing 42.
As shown in FIGS. 20 and 21, the inner surfaces of tubular regions
52 and 56 of nosepiece 44 are specially configured to restrict
cartridge retainers 188, 190 to a particular radial orientation
therewithin. Specifically, keyed portions 228, 230 of retainers
188, 190, respectively, rotate within grooves 232, 234 formed in
the proximal end of nosepiece 44. Each groove 232, 234 extends for
90 degrees about the circumference of the openings in nosepiece 44,
thereby limiting rotation of retainers 188, 190 to 90 degrees
within nosepiece 44. In addition, retainers 188, 190 can be removed
from nosepiece 44 only in a particular radial orientation.
Referring to FIG. 21, retainers 188, 190 are shown in their
unlocked radial positions. In FIG. 22, retainers 188, 190 have been
rotated 90 degrees counterclockwise in the direction of arrows 236
to cause the top edge surfaces of keyed portions 228, 230 to be in
engagement with interfering internal threads 238, 240,
respectively, thereby preventing the retainers 188, 190 from being
axially removed from nosepiece 44. Thus, retainers 188, 190 are
shown in their locked radial positions in FIG. 22.
Referring to FIG. 10, an insufficient dose remaining feature is
shown. In particular, if a user dials up a dosage greater than that
remaining in its cartridge, enlarged portion 120 of leadscrew 118
engages ledge 96 of internally threaded nut 88. This provides an
interference stop that prevents leadscrew 118 from being translated
any further. This indicates to the user that there is an
insufficient dosage remaining in the cartridge. At this point, the
user may choose to inject the dosage already set and then dial up
the difference after inserting a new cartridge.
The process for changing a spent cartridge is illustrated in FIGS.
23A-23D. It will be appreciated that the process of changing
cartridges can occur only while wing 132 is in its "down" position.
First, manifold 192 is removed from cartridge retainers 188, 190
and from the distal end of nosepiece 44, as shown in FIG. 23A.
Next, retainers 188, 190 are rotated 90 degrees as indicated by
arrow 242, and then removed. The spent cartridges are then removed
from the retainers, and new cartridges are inserted therein.
Retainers 188, 190 are then inserted back into nosepiece 44, as
shown in FIG. 23C. The pistons of the new cartridges engage heads
122 of leadscrews 118 and force leadscrews to rotate as indicated
by arrows 244 in FIG. 23C. Leadscrews 118 are spun back to their
home positions. Once keyed portions 228, 230 of retainers 188, 190,
respectively, are fully seated within respective lock keys 160,
retainers 188, 190 are rotated to lock them into place. Finally,
manifold 192 is inserted back onto the distal end of nosepiece 44
over retainers 188, 190, as shown in FIG. 23D.
In order to make a subsequent injection, wing 132 must be moved to
its "up" position (FIGS. 1, 24A) in the direction of arrow 212, as
shown in FIG. 3. This is necessary in order to cause ratchet teeth
69 of clutch indicator 68 to engage ratchet teeth 67 of indicator
dial 66 so that rotation of knob 60 results in rotation of nut
88.
It will be appreciated that the foregoing is presented by way of
illustration only, and not by way of any limitation, and that
various alternatives and modifications may be made to the
illustrated embodiment without departing from the spirit and scope
of the invention.
* * * * *